1. Field of the Invention
The present invention relates to a system for making an impression of an object. More particularly, the present invention is a device to capture the three-dimensional shape and size of an object without the use of plaster of Paris. Yet more particularly, the present invention is a device which incorporates a plurality of pre-fabricated units of formable material within a container. Still more particularly, the present invention is a system for making an impression of an entire foot, ankle, and lower leg simultaneously. Finally, the present invention is a system for quickly making an impression of a foot, ankle, and lower leg that requires no seam release agent, that is clean to use, that has minimizes the possibility of user error, that is cost effective, and that has containing means capable of functioning as a mailing carton for sending the impression to a manufacturing facility.
2. Description of the Prior Art
Molds and methods of making molds or cast fabrication have been around for a very long time. The early development of pottery where the shape of an object was formed with a clay mixture and then dried and solidified in a high temperature kiln may lay claim to the initial idea of molding shapes. For instance, the ancient method of making bricks with clay, straw, and water required the use of simple, rectangular molds for shaping the finished bricks. With the development of plaster of Paris, mold-making without the requirement of high temperature drying ovens became possible.
Although most of the "modern day" methods of mold-making have involved the use of plaster of Paris, some have involved the use of a combination of a flexible material filled with a mixture of sand and a fluid. Once formed around an object, the fluid is removed through a drain equipped with a filter and the remaining sand solidifies to a sufficient extend permitting the mold to retain its impression of the object. For the most part, the field of mold making, and particularly the field of foot impressions, has employed the use of plaster of Paris. More recently, however, there has become available foam-box kits for making impressions of the sole of a foot.
Full foot-ankle-lower leg impressions are important in the custom footwear industry. Particularly in the area of orthopedic shoes for diabetics, the demand for full foot-ankle-lower leg impressions will increase. Their use by diabetics has been shown to reduce the number of foot amputations, a drastic and not infrequent result of severe diabetes.
The specific problems associated with the current methods of taking foot impressions have lead to the development of the present invention. The drawback of using plaster of Paris is that it is very messy, that it requires the use of a release agent, and that the patient's foot must remain in a fixed position within the plaster of Paris for approximately thirty minutes to allow the plaster of Paris to set. The newer compressible foam impression systems reduce the time required to complete a foot impression; however, these systems are generally restricted to making sole impressions.
Several attempts at designing devices and methods of mold making have been undertaken. U.S. Pat. No. 84,979,252 issued to Daley, U.S. Pat. No. 2,472,754 issued to Mead, U.S. Pat. No. 1,824,835 issued to Pierce, and a product called Bio-Foam, manufactured by Smithers Bio-Medical Systems, Kent, Ohio, teach such devices.
Daley provides for an apparatus and a method for making custom insoles. The custom insole is made up of a plurality of layers of a thermoformable material that conform in size and contour to the bottom surface of a foot. The method of making the insole involves placing an unformed blank of the thermoformable material on a casting platform which in turn is on a horizontal surface. A foot is placed on top of the unformed blank and pressure is applied downwardly. The foot and then the blank is removed from the casting platform. Although this system is an attractive method of creating custom insoles, it is incapable of producing a mold of the entire foot, ankle, and lower leg.
Mead provides for a method of making and maintaining an impression of the shape of a human foot. The method involves the use of a flexible material, forming an enclosing "bladder" which is filled with a sand/fluid mixture, as the substrate for mold formation. At least three separate bladders are used for creating the impression of the human foot. Reduction of the fluid pressure within each bladder through an attached hand valve creates a "solidified" mold with the remaining sand. Even though this method is capable of producing a mold of the foot, ankle, and lower leg, it is cumbersome, time-consuming, may not be completely accurate, and requires various pieces of relatively expensive equipment.
Pierce provides for a device for taking foot impressions in a plaster of Paris cast to aid in the construction of footwear. The device is a mold of foot-shaped design embodying a base and a sectional foot-shaped shell for confining the plaster of Paris about the foot to produce an accurate impression. This system represents the traditional method used. In the traditional casting of the foot, ankle, and lower leg, a bivalve process is used. After application of a seam-release agent, the bottom half of the foot and the posterior ankle region are molded first, then the top half of the foot and the anterior ankle are molded to complete the cast. After hardening, the cast is opened along a seam by pulling a pair of wires, which were placed within the mold during the initial setup, thereby cutting the seam to allow release of the foot. As mentioned above, the major drawbacks of this system are the mess involved in making the plaster of Paris, the need for applying a release agent to the appendage, and the lengthy set time required for the plaster of Paris.
Smithers Bio-Medical Systems provides a system, called Bio-Foam Impression Foam System, for capturing the impression of the plantar foot surface. The foam is a compressible foam formulated to capture fine details of the sole of the foot. It is available in bulk, double-slab, and single-tray compression kits. A key problem with this system is that it fails to provide the means to take an impression of the entire foot, ankle, and lower leg.
Therefore, what is needed is a system for making an impression of a foot, an ankle, and a lower leg simultaneously. What is further needed is a system that does not involve the tedious and messy fabrication of a mold using plaster of Paris. What is still further needed is a system that does not require the use of a seam-release agent for separating the object being molded from the molding media. Finally, what is needed is a system that is convenient, easy to use, economical, and capable of making an impression of not only the sole of the foot, but a foot, an ankle, and lower leg in a self-contained disposable container useful for mailing and storing purposes.